webpack.config.prod.js

const { merge } = require('webpack-merge');
const OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const TerserPlugin = require('terser-webpack-plugin');
const CompressionWebpackPlugin = require('compression-webpack-plugin');
const commonConfig = require('./webpack.config.common');

module.exports = merge(commonConfig, {
  mode: 'production',
  optimization: {
    minimize: true,
    minimizer: [
      new OptimizeCssAssetsPlugin({
        cssProcessorOptions: {
          map: {
            inline: false,
            annotation: true,
          },
        },
      }),
      new TerserPlugin({
        // Use multi-process parallel running to improve the build speed
        // Default number of concurrent runs: os.cpus().length - 1
        parallel: true,
        // Enable file caching
        cache: true,
        sourceMap: true,
      }),
      new CompressionWebpackPlugin({
        filename: '[path][base].gz',
        algorithm: 'gzip',
        test: /\.js$|\.css$|\.html$|\.eot?.+$|\.ttf?.+$|\.woff?.+$|\.svg?.+$/,
        threshold: 10240,
        minRatio: 0.8,
      }),
    ],
  },
});